The inventive concepts disclosed herein relate generally to the field of weather display systems, and more particularly to weather display systems and methods configured to provide multiple source weather data.
Aircraft weather radar systems are often used to alert operators of vehicles, such as aircraft pilots, of weather hazards in the area near the aircraft. Such weather radar systems typically include an antenna, a receiver transmitter, a processor, and a display. The system transmits radar pulses or beams and receives radar return signals indicative of weather conditions. Conventional weather radar systems, such as the WXR 2100 MULTISCAN radar system manufactured by Rockwell Collins, Inc., have Doppler capabilities and can measure or detect parameters such as weather range, weather reflectivity, weather velocity, and weather spectral width or velocity variation. Weather radar systems may also detect outside air temperature, winds at altitude, INS G loads (in-situ turbulence), barometric pressure, humidity, etc.
Weather radar signals are processed to provide graphical images to a radar display. The radar display is typically a color display providing graphical images in color to represent the severity of the weather. Some aircraft systems also include other hazard warning systems such as a turbulence detection system. The turbulence detection system can provide indications of the presence of turbulence or other hazards. Conventional weather display systems are configured to display weather data in two dimensions and often operate according to ARINC 453 and 708 standards. A horizontal plan view provides an overview of weather patterns that may affect an aircraft mapped onto a horizontal plane. Generally the horizontal plan view provides images of weather conditions in the vicinity of the aircraft, such as indications of precipitation rates. Red, yellow, and green colors are typically used to symbolize areas of respective precipitation rates, and black color symbolizes areas of very little or no precipitation. Each color is associated with radar reflectivity range which corresponds to a respective precipitation rate range. Red indicates the highest rates of precipitation while green represents the lowest (non-zero) rates of precipitation. Certain displays may also utilize a magenta color to indicate regions of turbulence.
While aircraft-based weather radar systems may typically provide the most timely and directly relevant weather information to the aircraft crew based on scan time of a few seconds, the performance of aircraft-based weather systems may be limited in several ways. First, typical radar beam widths of aircraft-based weather radar systems are 3 to 10 degrees. Additionally, the range of aircraft-based weather radar systems is typically limited to about 300 nautical miles, and typically most effective within about 80-100 nautical miles. Further, aircraft-based weather radar systems may be subject to ground clutter when the radar beam intersects with terrain, or to path attenuation due to intense precipitation or rainfall.
Information provided by aircraft weather radar systems may be used in conjunction with weather information from other aircraft or ground-based systems to, for example, improve range and accuracy and to reduce gaps in radar coverage. For example, the National Weather Service WSR-88D Next Generation Radar (NEXRAD) weather radar system is conventionally used for detection and warning of severe weather conditions in the United States. NEXRAD data is typically more complete than data from aircraft-based weather radar systems due to its use of volume scans of up to 14 different elevation angles with a one degree beam width. Similarly, the National Lightning Detection Network (NLDN) may typically be a reliable source of information for weather conditions exhibiting intense convection. Weather satellite systems, such as the Geostationary Operational Environmental Satellite system (GOES) and Polar Operational Environmental Satellite system (POES) are other sources of data used for weather analyses and forecasts.
Current global convective information does not identify thunderstorm cores, overestimates the extent of thunderstorms, includes very little storm height information, results in poor predictions, is generally not very timely, and is difficult to interpret. Global convective weather information is conventionally derived from multiple sources. The first source is infrared satellite information that is 15 minutes to 1 hour old and only provides a coarse area where the highest clouds are located and not necessarily where the convective cells are located. The second source is global forecast models, which are used to identify and predict locations of convective activity using dew point and temperature information among other variables. The products derived from Global Forecast Models are very coarse and do not accurately identify the thunderstorm cores or the extent of the thunderstorm. Global lightning information is also available, but only shows the location of the strongest flashes and not the full extent of a thunderstorm core or whether the lightning flash is from a thunderstorm core or a non-threatening dissipating stratiform area. Existing products may derive a surrogate 2-D reflectivity or threat level from a lightning flash rate, however, such products are limited in usage in the United States and not globally. Moreover, global convective products are difficult to interpret by the operator, because the color codes do not correspond to threat levels pilots are accustomed to.